Software

Unicode

U+010C (uppercase Č - use Alt 268 for input) and U+010D (lowercase č - use Alt 269 for input) create this character. By using the combining character (U+030C) can be placed together with either c or C to generally achieve the same visual result.

TeX/LaTeX

In text the control sequence \v{c} will work. In math mode, $\check{c}$ also works.